To SMPTE
Time Code Time/Date!
PR-232 $219 
with MTG-TIME
If you already have a time-of-day SMPTE "master clock" time code generator, then you can use the combination of the HORITA PR-232 and the HORITA MTG-TIME program to keep your computer's clock locked to the SMPTE time code time and date. This combination doesn't require the installation of any extra plug-in boards in your PC.
The PR-232 is a miniature portable SMPTE time code to RS-232 reader/translator that does just what its name implies; it reads SMPTE time code and translates it into RS-232 data which is fed to your computer's RS-232 serial port. The PR-232 is powered from your PC's serial port, so no battery or other power source is required. All you need is accurate SMPTE time code.
The MTG-TIME program is installed in your computer as a Windows Taskbar program, compatible with Windows 98,ME,XP,2000 operating systems. The MTG-TIME program shows you the value of the SMPTE time code input to the PR-232, as well as the time and date values of your computer's clock/calendar. You can enter time zone offsets to keep the PC clock set to some other time zone, (for example, to Greenwich UTC time).
Once installed, the MTG-TIME program operates in the background to keep your PC's clock/calendar set to the correct time and date as derived from the SMPTE time code. Anywhere you have time-of-day or time/date SMPTE time code, you can keep a PC's time and date set correctly. If your master clock doesn't output the date in the user bits of the time code, the PC will automatically change the date at midnight.
If you don't have a SMPTE master time code generator, HORITA manufactures the GPS-MTG. The GPS-MTG includes a complete GPS (Global Positioning System) antenna/receiver (only 6" x 6") and provides both SMPTE time code time/date and RS-232 data outputs.